I also fully expect the 650hp GT500 to be only a very marginal real-world performance increase over the Boss 302, simply because the Boss is a more balanced track car. The Shelby's have always had issues laying down that power, particularly on a road course.

I agree with you about the traction issues with the current GT500. I had both a 2011 GT500 SVTPP and a 2012 Boss 302 and I much preferred the Boss because it could actually put the power to the road. The Shelby just had way too much low end torque for the stock suspension and tires to handle.

I've heard the 2013 GT500 will have launch control and some other electronic aids to help with traction. Unfortunately, it looks like Ford can't fit any wider tires on the 2013 due to body and suspension constraints so it will be up to the computers and any suspension tweaks to help deal with the 100 extra hp.